1. Field of the Invention
This invention relates generally to valves and to a valve for regulating flow through two port. More particularly, the invention relates to a single valve system for controlling fluid flow to fill and empty a lock chamber.
2. Related Art
Locks are commonly used in waterways to adjust the elevation of a vessel to match the different elevations of the waterway. These locks are frequently used to raise or lower a vessel in a navigable canal.
Heretofore, a minimum of two valves have been required to control the filling and emptying of the lock chamber: one valve located between the intake conduit and the chamber to release flow during the filling operation, and the other valve located between the chamber and the discharge manifold to discharge the flow during the emptying operation. The valves have generally been of the type which rotate about a horizontal axis.
This system results in significant initial-cost expenses associated with multiple operating machinery, culvert or conduit bulkheads, and extensive quantities of cement, concrete reinforcement, and foundation pilings to support the required additional machinery. Another disadvantage is the costs associated with providing and maintaining stone protection at the discharge end of the culvert to minimize erosion of the waterway bottom. A further disadvantage is that multiple operating machinery, located several hundred feet apart, must be maintained. Such system also requires extensive engineering time to analyze and design the required supporting structure for the multiple operating machinery.
Rotary valves are know which can control fluid flow through more than one port. Examples of three-way and four-way valves may be found in the following U.S. patents: U.S. Pat. No. 4,132,167, to Ishii; U.S. Pat. No. 2,643,640, to Lear; and U.S. Pat. No. 114,078, to Woods. In these valves, and other similar types, the fluid passages intersect at approximately 90.degree., and are used generally to control low-quantity fluid flow rates through small size conduits. Such valves are not designed for nor are they capable of handling the flow volumes and forces associated with controlling flow during the filling and emptying of a lock chamber or similar hydraulic applications.
U.S. Pat. No. 3,069,861, to Berke et al. discloses a three-way valve in a sluice dam seal but, again, the flow conduits intersect at 90.degree. angles and the hydraulic forces encountered are relatively low. Harza, U.S. Pat. No. 2,759,697, discloses a butterflytype valve for hydraulic applications, such as controlling water discharge through the bottom of a dam, and Jermar, U.S. Pat. No. 2,551,678, discloses a valve for controlling the water level in a lock, sluice gate, or the like, which is operated solely by the hydrostatic pressure of different water levels. The valves of the latter two patents do not control water flow through more than one port.